1. Field of the Invention
The present invention relates to a surgical microscopy system comprising a surgical microscope and a stand for the surgical microscope.
The surgical microscope can be used by a surgeon to obtain an enlarged image of a field for surgery during surgery. The stand comprises, starting from a base of the stand, a plurality of pivotally connected arms of the stand, onto one of which the surgical microscope is mounted. The arms are movable with respect to one another, for instance by pivoting, so as to change a spatial position of the surgical microscope relative to that of the base and, thus, relative to the field for surgery. In order to take some strain off the surgeon and in order to enable a spatial positioning of the surgical microscope to be as precise as possible, the stand comprises means for balancing the surgical microscope such that substantially independent of the position of the surgical microscope relative to the base, smallest possible forces need to be exerted onto the surgical microscope or one of the arms of the stand in order to spatially move the surgical microscope.
2. Brief Description of Related Art
Examples of a mechanical construction of such balanced stands are known, for instance, from German laid-open patent applications DE 43 20 443 A1 or DE 43 34 069 A1.
Apart from the mechanical function of holding the surgical microscope above the field for surgery, the stand also functions to guide various leads necessary in an operation of the surgical microscope along at least a part of the arms of the stand to the surgical microscope. These “leads” comprise, for instance, electrical wires for supplying driving power to a power consumer comprised in the surgical microscope. Examples of such power consumers are a motor operator for operating a zoom system of an optical arrangement of the surgical microscope, a data acquisition system, such as a camera or a distance metering system, and a data display unit for feeding data and images to be viewed by the surgeon into an optical path of the optical arrangement of the surgical microscope. These “leads” further comprise data lines for supplying data acquired by the data acquisition system, for instance, to a data recording system or a data processing system disposed, respectively, at a distance from the surgical microscope und, additionally, for transmitting data to the surgical microscope, for instance for being displayed to the surgeon by means of the data display system.
Further more, the “leads” also comprise light guides, in order to guide light required to illuminate the field for surgery to the same. The light source for this light is conventionally disposed on the base of the stand and light emitted by the light source coupled into a light guide and led along the arms of the stand to the surgical microscope and emitted by the surgical microscope in a direction of an object plane of the surgical microscope.
However, even carefully balanced stands have turned out to have disadvantages for the surgeon during practical use in that remaining forces of the stand tend to move the surgical microscope into one direction or the other.
In particular, it has turned out that the stand, even if it is satisfactorily balanced out for one position of the surgical microscope, still develops remaining forces in a different position of the surgical microscope.
It is therefore an object of the present invention to provide a surgical microscopy system comprising a stand having improved balancing.
For achieving this object, means are provided which dispose of the need to guide leads of one or another kind along at least some of the arms.
The inventors found that the remaining forces referred to above are generated by those leads and that these remaining forces are eventually generated by a local distortion of the leads in those areas where the leads extend from one arm of the stand to the next. Due to the displacement of the arms of the stand relative to one another, these distortions change and, thus, the remaining forces generated by these leads change. This is also the reason why they cannot be compensated for in substantially all spatial positions of the surgical microscope by balancing.
In order to put the concept of the present invention of reducing the remaining forces attributable to the leads into practice, one embodiment of the present invention involves replacing a conventional lead of little flexibility by a more flexible lead, and, in particular, replacing a conventional lead of a given thickness and stiffness by two separate leads of decreased overall thickness and stiffness.
Further more, an embodiment is provided wherein a transmission by means of a lead is replaced by a wireless transmission by an emitter disposed at a distance from the surgical microscope directly to a receiver disposed at the surgical microscope or from an emitter disposed on the surgical microscope to a receiver disposed at a distance from the surgical microscope.
The embodiments of the present invention described in the following have in common that they comprise a surgical microscope and a stand having a base and a plurality of pivotally connected arms, the surgical microscope mounted to one of the arms, wherein the pivotally connected arms are arranged to be movable with respect to each other such that the surgical microscope is movable relative to the base.
A base of the stand may be a footing of the stand placed on the floor of a room. The base of the stand may, however, also be a fixing attachment for fixing the stand to a ceiling or a wall of the room or any other object, such as a further stand.
In one embodiment of the present invention a light emitter for illuminating a field for surgery is provided on the surgical microscope, and the surgical microscopy system comprises a light guiding system for supplying light to the light emitter. Herein, at least two separate light guides are provided, which guide the light together to a single light emitter. It has turned out that a light guide with a given light guiding diameter has a larger stiffness than two light guides with only half the given diameter each combined. The at least two light guides are supported on at least one pair of pivotally connected arms of the stand and are attached to each arm of the pair at an attachment position on the respective arm, wherein the two attachment positions are disposed at a distance from each other. The at least two separate light guides still exert remaining forces depending on a position from the position of the pair of arms of the stand in relation to one another, these remaining forces, however, are generally lower than the remaining forces exerted by a conventionally used single light guide.
A further embodiment provides a light source for supplying light to the light emitters, which light source is disposed directly on the surgical microscope. Such an approach has not been taken so far since powerful illumination systems for surgical microscopes make use of light guides, for the supply of light throughout. Disposing the source of light directly on the surgical microscope increases the weight thereof and is thus associated with a certain disadvantage. This disadvantage, however, is more than compensated for by the fact that the remaining forces conventionally created by the light guide are avoided due to the ability of the stand to balance out the higher weight of the surgical microscope.
In an exemplary embodiment, a semiconductor device such as a light emitting diode is used as the light source. The inventors have found that modern semiconductor devices are capable of producing a comparatively high output, which, surprisingly, is sufficient to illuminate a field for surgery in practice to a satisfactory extend. Accordingly, the inventors deviated from the approach laid out by the state of the art, i.e. supply of increasing light output to the surgical microscope by means of ever thicker light guides. In contrast, they have proposed an entirely different solution as compared to this conventional approach, in particular arranging the light source in the form of a semiconductor device on the surgical microscope itself.
In an exemplary embodiment, for generating electrical power (in particular current) and for supplying electrical power (current) to the light emitter or light source, respectively, at least one electrochemical cell disposed on the surgical microscope is provided, such as one of a battery, an accumulator and a fuel cell. This makes it possible to avoid a power supply lead for the light source extending along the arms of the stand.
A further embodiment provides two independent electrochemical cells on the surgical microscope, wherein only one of the cells is sufficient to enable operation of the surgical microscope, which means, herein in particular, the operation of a light source. An exchange of a used-up cell is then possible without interrupting an operation of the surgical microscope.
Furthermore, in an exemplary embodiment, a plurality of semiconductor devices are provided as light sources, wherein these emit light in different wavelengths ranges, respectively. Light of different colour of the individual light sources is then superposed in such a manner that a field for surgery is illuminated by superposed light, a colour of which approximates that of white light agreeable to the surgeon.
Such a superposition can be effected such that it takes place at the field for surgery only, for instance by having sources of different colour emit their light directly to the field for surgery. In an alternative exemplary embodiment, however, a light mixer for generation of a superposition is provided, wherein the light mixer provides a light reflecting geometry, wherein at least a part of the light generated by the light sources is reflected once or more.
In an exemplary embodiment, the light mixer takes the form of a light guide which is disposed around at least a part of the circumference of the objective lens of the surgical microscope.
In a further exemplary embodiment, a semiconductor device is provided, which emits light and emits at least a portion of this light onto a phosphor (luminophor), which transforms incident light into light of a certain colour by luminescence, which can then be emitted onto the field for surgery. The semiconductor device may be, for instance, a light emitting diode emitting light in the ultraviolet, light of which is incident on a layer of a phosphor, which may contain one or more phosphors such that light emitted by this layer leaves an impression of about white colour. Equally, it is possible that the semiconductor may be a light emitting diode which emits blue light. A portion of this blue light may be used for illuminating the field for surgery, whereas a different portion of this light is incident on a layer of a phosphor, which is configured such that it transforms blue light into red or yellow light, for instance, which is equally used for illuminating the field for surgery. The light emitted by the blue LED and the light emitted by the phosphor can also be mixed in accordance with techniques described above in order to obtain an illumination light of the field for surgery which is about white and as homogeneous as possible.
Apart from the embodiment with a semiconductor device as the light source it is possible to use an organic device, such as an organic light emitting diode (OLED), or a light emitting polymer (LEP).
According to a further embodiment of the present invention, the light emitted by the light emitter is introduced into the surgical microscope from an outside, for instance by means of a light guide, whilst in addition, a photocell is provided on the surgical microscope, onto which a portion of the light supplied to the surgical microscope is incident, in order to generate current for operating one or more current consuming components of the surgical microscope by means of an optoelectrical process. It is then possible to do without a current supply lead conventionally disposed along the arms of the stand and, thereby, to reduce the remaining forces generated by the conventional current lead.
In an exemplary embodiment, a beam splitter is provided, through which light supplied to the light emitter passes in order to split the portion of light off which is then directed onto the photocell. In a further exemplary embodiment, the beam splitter is wavelength-selective and effects a splitting function substantially only for a range of wavelengths of the light supplied, which range is of no significant importance to the illumination of the field for surgery.
According to a further embodiment of the present invention, a device powered by electric current is disposed on the surgical microscope, and the surgical microscopy system comprises a power supply for operating this device. Herein, the power supply for leading current to or from the surgical microscope, respectively, comprises an electrically insulated wire each, which wires are separate from one another and extend as separate wires inbetween two attachment portions on different arms of the stand of a pair of arms pivotally connected to each other.
In contrast to a pair of wires of a current supply lead which is conventionally firmly fixed together, a wire separate from another wire provides lower remaining forces, similar to what has been described above in relation to the supply of light by two separate light guides.
In an exemplary embodiment, the two wires are a “twisted pair”, i.e. mutually twisted wires.
According to a further embodiment, the power supply comprises an AC generator, an induction emitter supplied without operating power by the alternator, the induction emitter being attached to a first arm of the stand, and an induction receiver, the induction receiver being mounted to a second arm of the stand such as to face the induction emitter and to be movable relative thereto, the second arm being pivotally connected to the first arm. The induction emitter then supplies operating power to the device which is driven by electrical current.
In accordance with a further embodiment, the power supply comprises a contact rail disposed on a first arm and a sliding contact disposed adjacent to the first contact rail, wherein the sliding contact is disposed on a different arm which is pivotally connected to the first arm. Herein, a current lead, which, for instance, bridges a joint between adjacent arms of the stand is rendered redundant altogether.
According to a further embodiment, at least a mechanically supporting component of an arm of the stand is configured to form part of a current path to or from the device powered by electrical current. This current path provided by the mechanically supporting component of the arm of the stand then replaces a conventionally provided current lead such that remaining forces exerted by this conventional current lead no longer exist.
According to a further embodiment, the current required for operation of the current consuming device is not provided by a current lead, but the required energy is transmitted by wireless transmission, for which purpose a radiation emitter is provided at a distance from the surgical microscope and a corresponding radiation receiver is provided on the surgical microscope. The receiver transforms the received radiation into an electrical current for operation of the device. The energy radiation may be, for instance, infrared radiation, microwave radiation or laser radiation.
In an exemplary embodiment, the emitter has a distinctly directional characteristic, which is adjustable in dependence of the position of the surgical microscope such that a large portion of the radiation energy emitted by the radiation emitter is incident on the radiation receiver.
According to a further embodiment, the power supply comprises an electrochemical cell disposed on a base of the stand, such as an accumulator or the like.
This is particularly advantageous when the base of the stand is configured to be placed on the floor of the room and therefore is supposed to have an increased weight for securing a stability of the stand. In these embodiments, power supply leads for supplying energy to the surgical microscopy system are not necessary, which facilitates the work of the surgeon who conventionally has to pay attention not to stumble over leads running across the floor of the operation theatre.
As an alternative solution for this problem, induction emitters attached to the floor or disposed in the floor are provided which work in cooperation with an induction receiver disposed on the base of the stand for transmitting energy to the surgical microscopy system.
In accordance with a further embodiment of the present invention, the surgical microscope is provided with a data acquisition unit or a data display unit, and the surgical microscopy system comprises a data transmission system for transmitting data to the data display unit or away from the acquisition unit. In contrast to a coaxial cable or the like conventionally used for these purposes a pair of wires is used, which wires are separate from one another. These wires extend separately from one another between two attachment portions or points, which attachment portions are disposed on a pair of pivotally connected arms of the stand, similarly to the embodiment described above in connection with the description of the pair of current supply wires. Also, the possibilities of a “twisted pair” of wires, of the use of contact rails and sliding contacts, as well as using a mechanically supporting component of arms of the stand for electrical data transmission, which have been described in connection with the current supply, are equally applicable here.
In accordance with a further embodiment, a transmission system comprises a data modulator and an induction transmitter powered by the data modulating unit. The induction transmitter is mounted on a first arm of the stand and the induction receiver mounted to a second arm of the stand in such a manner that it faces the induction transmitter and is movable with respect thereto, wherein the at least first arm and the second arm are pivotally connected, and wherein a data demodulator is coupled to the induction receiver.
If the surgical microscope comprises a data display unit, in an exemplary embodiment, a data demodulator is coupled to the data display unit. This coupling may extend over further arms of the stand wherein these, in turn, comprise pairs of induction transmitter and induction receiver.
If the surgical microscope comprises a data acquisition unit, in an exemplary embodiment, the data acquisition unit is coupled to the data modulator, wherein here, also, the coupling may extend over several arms of the stand, pairs of which comprise induction transmitters and induction receivers facing each other.
According to a further embodiment, data transmission is provided by a light guide, which is disposed along the arms of the stand. Due to the high bandwidth of the data transmission through light guides it is possible to save a plurality of conventional data transmission lines.
Furthermore, it is possible to have a light guide for data transmission together with a light guide for supplying illumination to the surgical microscope. For instance, a light source can be modulated for data transmission and this modulation can be detected at the surgical microscope, or light for its transmission can be coupled into the light guide for supplying the illumination light coupled out again at the surgical microscope. In an exemplary embodiment, light for data transmission is coupled into merely one glass fibre or a few glass fibres of light guides for transmission of the illumination light and that only light of this one or few glass fibres is demodulated at the other end of the light guide.
According to further embodiments, wave guides for providing electromagnetic radiation are disposed on arms of the stand and are connected or jointed, at locations where adjacent arms of the stand are pivotally connected, without there being inacceptably high transmission losses.
In accordance with a further embodiment, an optocoupler is provided for transmission of data from one arm of the stand to an adjacent arm of the stand. Components of the optocoupler, i.e. transmitter and receiver, are then movable relative to each other, together with the pivotally connected arms of the stand, without being too detrimental to a transmission quality.
According to a further embodiment, transmission is provided in a wireless form, by having a transmitter or/and receiver for data disposed on the surgical microscope and a corresponding receiver or transmitter disposed at a distance from the surgical microscope. Between transmitter and receiver, a transmission is carried out electromagnetically through wireless transmission. Wireless transmission processes according to at least one of blue tooth standard, IEEE 802.11b standard, and hyperLAN standard are used in exemplary embodiments.
According to a further embodiment, the data are compressed before their transmission by the transmitter and decompressed after their receipt. This enables transmission of large amounts of data in the form of image data in a satisfactory manner. Compression according to a process is used in an exemplary embodiment, wherein conventionally only information with regard to a part of an image to be transmitted is transmitted, which part has changed in comparison to a previously transmitted image. An example for such a process is known as MPEG4 which provides a further advantage in that it allows to use one of a substantially static background and a dynamic foreground.
Such a compression process is typically particularly effective for images taken through a surgical microscope, since the scenario in a field for surgery changes only very slowly in practice and then only in small areas of the field for surgery where the surgeon carries out manipulations with his instruments.